Speed-regulating apparatus



v. FYNN. SPEED- REGULATING APPARATUS.

APPLICATION FILED APR,25.1918- Patented Apr. 4, 1922;

SPEED DIFFERENCE INVENTOR.

WITNESS ATTORNEY.

UNITED STATES PATENT OFFICE.

VALERIE A. FYNN, OF ST. LOUIS,.MISSOURI, ASSIGNOR TO WAGNER ELECTRIC MANU- FACTURING COMPANY,'OF ST, LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

SPEED-REGULATING APPARATUS.

Specification of Letters Patent.

Patented Apr. 4, 1922.

Application filed April 25, 1918. Serial No. 280,753.-

To all whom it may concern:

Be it known that- I, VALTJRE. A. FYNN, a subject of the King of England, residing at the city of St. Louis, State of Missouri. United States of America, have invented a certain new and useful Speed-Regulating Apparatus, of which the following is such a full, clear, and exact description as'will enable any one skilled in the art to which it appertains to make and use the same, reference -being had to the accompanying drawin forming part of this specification.

y invention relates to means for regulating or adjusting the speed of prime movers, such as an internal combustion engine.

In carrying out my invention, I make use of a differential gearing, drive one element thereof at a constant speed, couple a second element to the engine and place a member controlled bythe third element in inductive relation to a second member which is operatively connected to the throttle valve and ada ted to alter the position thereof in ac cordance with the movement of the first member. I prefer to drive the first element by means of a constant speed electric motor, and to derive the electric energy to operate same from a dynamo electric machine coupled to the engine. a

A direct current shunt motor is well suited to my purpose for the reason that such a machine can be designed to run at a practicall constant speed, even though the E. M. of the source from which it receives its energy is not constant.

My invention will be better understood by reference to the accompanying drawings in which Fig. 1 is a diagrammatic representation of one embodiment of my invention showing all the necessary electric connections. Fig. 2 indicates how the second member can be connected to the throttle valve ofan internal combustion engine and shows the relative position it occupies with reference to the elements of the differential gearing. Fig. 3 shows one way of arranging the elements of the differential gearing and the two elements of the electro-magnetic device means of the adjustable resistance 5. This generator can be connected to the storage battery 41 through switch 40 and is connected to the shunt motor 6, 7 the shunt winding 8 of which can be regulated by means of the adjustable resistance 9'. This motor is coupled to the element 10 of a differential gearing. This element may be a conical friction wheel or a conical spur wheel, or the like. The shaft 11 which is connected to the engine carries the second element 12 of the difierential, while the third element consists of two conical wheels 13, 14, the pivot 39 of which is journaled or held in and supports the ring 15 which is preferably made of magnetic material. Closely surrounding this ring is a tube of conductive material 16, such as copper. The member 17 provided with the winding 18 is placed in inductive relation to the conductor 16 and is mechanically connected to the throttle valve 19 either directly or by means of the levers 20 and 21 as shown in Fig. 2. The winding18 is connected to the terminals of the generator 24: through an adjustable resistance 22. The member 17 may, with advantage take the, form of a ring made of magnetic material and provided with slots 23, in which the winding 18 can be located. This ring has a projection'24 "to which the lever 20 is coupled and is held in its position of rest. in which the throttle valve 19 is wide open, by means of a sprin 26 attached to the projection 25. This spring holds the nose 28 against the stop 27. Instead of. a copper tube 16, the ring 15 may be provided with a regular. squirrel cage winding, having bars 29, and short circuiting rings 30. The ring 15 attached to the third element of the differential can be centered by means of the pivots carrying the conical wheels 13, 14 and a ball bearing 31', 32 in the manner shown in Fig. 3. In this figure, the element 32 of the ball bearing is carried by the shaft 11 coupled to the engine. The motor shaft 34 iscentered within the shaft 11. In order to center the member 17 about the member 5, balls v35 may be. provided between the two members. The members 15 and'17 may, if desired, be built up of iron or steel laminations, but this is by no means necessary and they can be'made of solid iron or steel.

The generator 2, 4is also adapted to. supply energy to the consumption circuit 37 38 and the series coil 33 located on the field structure of the motor .6, 7, is connected to carry the current supplied to said consumption circuit or a current proportional to same. i

The operation of my regulating device is somewhat as follows. With the engine running and the generator 2, 4 excited, it is possible to adjust the speed of the motor 6, 7 to any desired value by means of the adjustable resistance 9, or in someother known manner. As long as'the engine runs at the same speed as this controlling motor, the wheels 13 and 14 will revolve about their pivot 39, but the ring 15 will be stationary in space, there will be no relative movement between the members 15 and 17 and there will be no torque exerted on the element 17, with the result that the throttle valve will remain wide open. Should this posltion of the throttle valve, however, cause the engine to exceed the speed of the motor, for instance, when the load on the engine is reduced, then the member 15 will begin to revolve in the same direction as the element 12 of the differential which is driven by the engine. Since the winding 18 produces a unidirectionalmagnetization in the member 17, then the slightest relative movement between the members 15 and 17 will induce heavy currents in the copper tube 16, or in the squirrel cage winding 29, 30 of the member 15, with the result that a torque will be exerted on the member 17, tending to move said member in the direction in which the member 15 is moving. For an increase of the engine speed above that of the regulating motor, the member 17 will move in a direction to close the throttle valve and thus reduce the engine speed. The member 17 can of course, only move over a restricted arc and for any balanced condition, it will be stationary in space, holding the throttle valve in a suitable position. In order to enable member 17 to do this in any position other than that corresponding to a wide open throttle, it is necessary that there be a difference in speed between it and the element 15. This means, that with the throttle valve wide open, the engine can run at exactly the same speed as the controlling motor, but for any other position of the throttle valve, the engine speed must exceed that of the controlling motor, this excess reaching its highest value at no-load when the throttle valve is nearly closed. The smaller the difference between the no-load and full-load speeds of the engine, the closer and more satisfactory the regulation and the greater the accuracy of the device. The curve 36 of Fig. 4 shows how the torque transmitted to the member 17 varies as the speed difference between it and the element 15 increases, It is seen that while this torque is zero as long as there is no relative motion between the two members, it increases with extreme rapidity for very small differences of Speed. The lower the resistance of the winding or conductor on the member 15 and the greater the unidirectional magnetization, the steeper the curve 86 of Fig. 4 for very small speed difi'erences. Owing to this condition, it is possible to obtain an extremely close regulation with m improved device even on the assumption of a perfectly constant controlling motor speed. The torque necessary to move the throttle valve of an internal combustion engine is usually small, but the combination here described comprising" a squirrel cage member co-operating with one producing a unidirectional magnetization is ca pable of developing extremely powerful torques with apparatus of small dimensions and therefore has a wide range of usefulness. The magnitude of this torque can be adjusted with great facility by varying the magnitude of the unidirectional excitation. Good results will be obtained by providing the member 15 with a regular squirrel cage, such as is shown in Fig. 2 and loeating the exciting winding 18 in slots or openings of the member 17 placed near the inner periphery of said member. A small air gap between the two members will also help to reduce the magneto motive force necessary to produce a given magnetization. The member 17 can be wound for any convenient number of poles. The usual number will probably be two or four.

I The speed of the controlling motor, however, does not remain quite constant with varying engine speeds because of the reactions between the two through the differential gearing which connects them. Any arrangement which will raise the speed of the controlling motor as the load on the engine increases, will reduce the difference between the engine no-load and the engine full-load speeds. By raising the motor speed sufficiently with increasing load, it is possible to have the engine run faster at fullload than at no-load. This last condition is very often desirable.

WVhen the engine is loaded by means of a dynamo electric machine such as 2, 4 which supplies energy to a consumption circuit such as 37, 38 the speed of the controlling motor may be varied with the engine load in a very simple manner. In order to keep the terminal voltage of the generator constant, irrespective of the magnitude of the load or of the heating of the machine, or even to cause said terminal voltage to increase with increasing load it is only necessary to make the magnetization of the speed controlling motor 6, 7 dependent on the current in the consumption circuit. decreasing said magnetization with increasing engine load. The series coil 33 of Fig. 1 located on the field structure of the motor 6, 7 can be used for this purpose and should be conhected to carry the load current or a current proportional to the load current. When the controlling motor operates as a motor a decrease in its magnetization will increase its speed and vice versa. The converse is true when the machine runs as a generator Instead of centering the member 17 on the member by means of balls as shown in Fig. 3, this member can be centered preferably on ball bearings on the shafts 34 and 11, or on pedestals surrounding said shafts.

The battery 41 can be used to crank the prime mover when the latter is of the internal combustion type, and helps to minimize the fluctuations of the voltage at the terminals of the controlling motor but it is not necessary to make use of a battery.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a speed regulating apparatus, the combination with a device to be regulated, of speed controlling means therefor, a reguiatingmember driven by the device to be regulated, and a second regulating member driven at a speed continuously different from that of the first regulating member when the speed controller is in other than its maximum speed posit-ion, said speed controlling means for the device to be regulated being responsive to change in relative speed of the two regulating members.

In speed regulating apparatus for prime movers, a power controlling valve for the prime mover, a device driven at a speed independent of the speed of the prime mover, a dynamo electric machine having both members movable, one member being connected to the power valve and the other member being driven at a speed varying with variations in relative speed of the prime mover and the independently driven device.

3. In speed regulating apparatus for prime movers, the combination with means controlling the power supply to the prime mover, ot means for actuating the controlling means, said actuating means comprising a generator driven b the prime mover, a motor connected to t 1e generator, means for varying the motor excitation in said generator, a motor connected to the generator, means governed by the current in the consumption circuit for varying the speed of the motor, and a device connected to the power controlling means and responsive to changes in relative speed of the motor and the prime mover.

5. In speed regulating apparatus for,

prime movers, a power controlling valve for the prime mover, a dynamo electric machine having both members movable, one member being mechanically connected to the power valve, a differential having one member driven by the prime mover, a second member connected to the second member of the dynamo electric machine and means for driving the third member of the diiferential at a speed independent of the speed of the prime mover.

6. In speed regulating apparatus for prime movers, a power controlling valve for the prime mover, a dynamo electric machine having both members movable, one of said members being provided with a short circuited winding, means for supplying a unidirectional E. M. F. to the other member, a differential having one member driven by the prime mover and another member connected to one member of the dynamo electrio machine, meansfor driving the third member of the differential at a speed independent of the speed of the prime mover, and means connecting the second member of the dynamo electric machineto the power controlling means. I

In testimony whereof, I have hereunto set my hand and afiixed mv seal.

VALERE A. FYNN. 

